CHAPTER III. 



PHYSICAL AND CHEMICAL CHARACTERS OF CEL- 

 LULAR DEATH. NECROBIOSIS. GROWING OLD. 



Characteristic of elementary life— Changes produced by death 

 in the composition and the death of the cell— Schlemm ; 

 Loew ; Bokorny ; Pfliiger ; A. Gautier ; Duclaux— The 

 processive character of death — Accidental death— Necro- 

 biosis— Atrophy— Degeneration— So-called natural death — 

 Senescence— Metchnikoffs theory of senescence — Objec- 

 tions. 



Elementary death is nothing but the suppression 

 in the anatomical elements of all the phenomena of 

 vitality. 



Characteristics of Elementary Life. — The char- 

 acteristic features of elementary life have been 

 sufficiently fixed by science. First of all, there is 

 morphological unity. All the living elements have an 

 identical morphological composition. That is to say 

 that life is only accomplished and sustained in all its 

 fulness in organic units possessing the anatomical 

 constitution of the cell, with its cytoplasm and its 

 nucleus, constituted on the classical type. In the 

 second place, there is chemical unity. The constituent 

 matter, the matter of which the cell is built up, diverges 

 but little from a chemical type — a proteid complex, 

 with a hexonic nucleus, and from a physical model 

 which is an emulsion of granulous, immiscible liquids, 

 of different viscosities. The third character consists in 



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